In recent years, the video transmission system applicable to ultra-high-definition TV broadcasting and referred to as an MPEG media transport (MMT) system is attracting attention. In the following, the system may be referred to as the MMT system or MMT standard.
The MMT system is a system standardized internationally by the Moving Picture Experts Group (MPEG). It is a transmission system which processes data, including video, sound, caption or program guide components, in the form of MMT protocol (MMTP) packets, and which transmits the MMTP packets as Internet protocol (IP) packets. By application of the MMT system, contents such as videos and sound can be distributed using a plurality of such transmission channels as broadcast channels or communication channels, and contents distribution service using both broadcasting and communications is enabled.
In broadcast service to which the MMT system is applied, a plurality of components including videos, sound, captions and program guides are packetized, and the resultant packets (which may be referred to as MMTP/IP packets) are multiplexed by a multiplexing apparatus, for transmission.
When the MMT standard is updated, there may be a case where different versions of MMT standard are included in one broadcasting system. The multiplexing apparatus receives a large number of outputs from broadcast devices compatible with the MMT standard (such as MMTP/IP packet transmission devices) and executes multiplexing processing for the received outputs. In this case, the MMTP/IP packets received by the multiplexing apparatus have to be of the same MMT standard version. In the broadcasting system, therefore, the broadcast devices compatible with the MMT standard have to be simultaneously updated such that they correspond, for example, to the latest version of MMT standard. This imposes a constraint at the time of system updating.
Under the circumstances, it is desired that the multiplexing apparatus compatible with MMT standard can execute multiplexing processing even if the MMTP/IP packets supplied thereto are of different versions of MMT standard.